Have all the CATS entries been approved/rejected? Could it be that there is still some entries to be approved/rejected, and that's why the work item hasn't been completed? If you search with the work item ID from CATSDB, will you find anything?
Does this happen frequently (have you been able to reproduce the problem in test system) or only rarely?
There could also be a bug in the standard code. If I remember correctly, there has been similar threads before. I don't remember if they were able to solve the problem...
Regards,
Karri